Camel-back fleece laying machine

ABSTRACT

In a camel-back fleece laying machine with a laying arm attached to a joint, two endless card web transport belts are guided along this arm, and the bottom end of the laying arm carries a discharge gap, which is moved by an upper carriage transversely to the transport direction of an output conveyor belt in a plane above the output conveyor belt. A laying carriage is guided at a certain height between the output conveyor belt and the upper carriage on a path extending parallel to the upper carriage, and two closely adjacent deflecting rolls are mounted in the upper carriage, over each of which a cover belt is guided. The cover belts form a laying gap at the deflecting rolls, through which gap a card web supplied by the card web transport belts is conducted. The drive of the laying carriage is independent of the drive of the upper carriage, and the path of movement of the upper carriage extends beyond the path of movement of the laying carriage at least at one end.

CROSS REFERENCE TO RELATED APPLICATION

This application claims priority to European patent application EP 06009 529.6, filed May 9, 2006.

FIELD OF THE INVENTION

The invention pertains to a camel-back fleece laying machine for layinga fleece from of a card web supplied by a carding machine and to afleece laying method carried out by means of a camel-back fleece layingmachine.

BACKGROUND

A camel-back fleece laying machine which has a laying arm, over whichcard web transport belts are guided, is described in EP 1 612 306 A1. Abottom end of the laying arm is connected to a carriage, which is guidedtransversely to the transport direction of an output conveyor belt, thustraveling back and forth above the belt. Two deflecting rolls, aroundeach of which a cover belt passes, are rotatably mounted in thecarriage. The lower run of each of these belts extends just above theoutput conveyor belt, and the upper run is parallel to, and a certaindistance away from, the lower run. The deflecting rolls mentioned are asuitable distance apart, so that the cover belts on the deflecting rollsform a laying gap, through which the fiber card web coming from anoutput gap at the lower end of the laying arm is guided onto the outputconveyor belt. The carriage is divided into two sleds, an upper sled anda lower sled. The bottom end of the laying arm is supported in the uppersled, whereas the previously mentioned deflecting rolls are supported inthe lower sled. The upper sled can be adjusted to a slight extent withrespect to the lower sled in the direction of movement of the carriageand also in the opposite direction, so that, within the carriage, theroute which the card web describes can be changed in such a way as toreduce the danger that, when the carriage reverses its direction, thecard web will enter a triangular pocket formed between the deflectingroll of one of the card web transport belts running along the layingarm, namely, the roll located in front with respect to the direction ofmovement, and the deflecting roll of one of the cover belts, namely, theroll situated, again, in front with respect to the direction ofmovement. The two sleds thus oscillate to a slight extent with respectto each other during the laying cycle.

As the carriage oscillates back and forth across the output conveyorbelt, it arrives at the edges of the output conveyor belt, whichrepresent the endpoints of its path. The carriage must be braked to zeroat these points, and after reversing direction, it must be acceleratedagain. This variation in the speed of the carriage must be brought intoharmony with the uniform speed with which the card web to be laid issupplied to the fleece laying machine by a carding machine, forotherwise there will be thick areas at the edges of the fleece laid bythe fleece laying machine. The fleece laying machine described in thepreviously mentioned EP 1 612 306 A1 therefore has a web buffer in itsinfeed area. Because of its location, this buffer is called the infeedweb buffer, and it takes up the excess length of card web material orpays it out again when the card transport belts running along the layingarm, which travel at the same speed as the carriage, start to travel ata speed which differs from that at which the carding machine, whichoperates at a uniform rate, is supplying the card web to the fleecelaying machine. The volume of buffered card web in the infeed bufferarea thus increases when the carriage is in a deceleration phase thendecreases again after the carriage reverses direction and is in anacceleration phase.

The web buffer in the infeed area of the fleece laying machine makes themachine much more expensive, because a large number of deflecting rollsand moving parts are required to form this web buffer. In addition, themoving masses which must be braked and accelerated again by the driveunits of the carriage are relatively large, which leads to correspondingloads and to premature wearing-out of the toothed belts used in thesedrive units.

SUMMARY OF THE INVENTION

The invention is therefore based on the task of providing a fleecelaying machine of the type indicated above, which, while maintaining thementioned buffer function, is technically of simple design, and on thetask of providing a fleece laying method based on the use of acamel-back fleece laying machine, namely, a method which imposes lighterloads on the drive units of the fleece laying machine than is the casewith the known machines.

This task is accomplished by a fleece laying machine

-   -   with a laying arm,    -   a top end of which is attached to a joint,    -   two endless card web transport belts being guided along the arm,    -   a bottom end of the arm, which is connected by a joint to an        upper carriage, being provided with an output gap; and    -   the arm being guided by the carriage along a path which is        transverse to the transport direction of an output conveyor belt        in a plane above this output conveyor belt, where the upper        carriage is connected to a first drive unit, which causes the        laying arm to oscillate; and    -   with a laying carriage,    -   which is guided at a certain height between the output conveyor        belt and the upper carriage on a path extending parallel to the        upper carriage, and

in which two deflecting rolls are supported close together, over each ofwhich a cover belt passes,

-   -   where the two cover belts form a laying gap at the deflecting        rolls, through which the card web being supplied by the card web        transport belts is guided, and have upper and lower runs, which        extend in upper and lower planes parallel to the output conveyor        belt, the lower plane being very close to the output conveyor        belt, and    -   where the laying carriage is connected to a second drive unit,        which causes the carriage to move back and forth across the        output conveyor belt, this drive unit being independent of the        first or upper carriage drive unit, and    -   where at least at one end, the path of the upper carriage        extends beyond the path of the laying carriage to form a web        buffer.

In the inventive fleece laying method for laying a fleece by means of acamel-back fleece laying machine, a card web, supplied by a cardingmachine, is guided between two card web conveyor belts guided inparallel at uniform speed along a movable laying arm. The card web thusarrives at a discharge gap, which is guided along a first path ofmovement and is situated at the bottom end of the laying arm, and fromthere travels onward to a laying gap. The laying gap is located betweentwo cover belts, which are deflected around two deflecting rolls mountedin a laying carriage, which is moved back and forth along a second pathof movement. The card web is thus deposited on an endlessly movingoutput conveyor belt extending transversely to a laying path, where,when the laying carriage is braked as it approaches one of its reversalpoints, the speed of the card transport belts remains unchanged and thedischarge gap is moved with respect to the laying gap in such a way thatthe distance between the discharge gap and the laying gap is increased,so that a certain length of the card web can be buffered between thedischarge gap and the laying gap, whereupon, after the laying carriagehas reversed direction and is accelerating again, the distance betweenthe discharge gap and the laying gap is decreased in such a way that thelength of buffered card web is reduced.

The invention achieves the desired result, therefore, by shifting thebuffer area required to compensate for the speed variations of thelaying element into the card web discharge area of the laying element.The camel-back fleece laying machine known from EP 1 612 306 A1 isaccordingly modified in such a way that the upper sled, in which theactual laying gap is formed, is, according to the invention, elaboratedinto two completely independent parts, namely, the upper carriage andthe laying carriage, which move along paths which are sufficientlydifferent from each other and sufficiently independent of each otherthat a buffer area can form between them. This buffer area is able totake up temporarily and to pay out again the length of card web which isnecessary to bring the varying speed of the laying element into harmonywith the uniform speed at which the card web is supplied to the fleecelaying machine. In practice, it has been found that it is sufficient tobuffer a length of 1 m of card web.

The inventive measures have the result that, during the braking andacceleration phases of the laying carriage, the card web leaving thedischarge gap of the laying arm is not deposited immediately onto theoutput conveyor belt but is rather at first deposited onto the upper runof one of the cover belts, which serve to protect the laid fleece fromthe harmful effects of air turbulence, which can be caused by themovement of the laying carriage. It is only from there that the card webthen arrives in the gap between the cover belts at their deflectingrolls in the laying carriage.

The section of the upper run of the cover belt on which the card websection between the discharge gap of the laying arm and the layingcarriage rests is therefore a buffer area of variable volume. The lengthof the buffered card web section therefore changes within a laying cyclein correspondence with the change in the speeds of the laying carriageand the upper carriage.

It is advantageous to protect this buffered card web section lying onthe upper run of one of the cover belts against air turbulence also.Therefore, according to an embodiment of the invention, the assemblyconsisting of the upper carriage and the laying carriage is providedwith devices which cover the card web section extending between thedischarge gap of the laying arm and the entrance to the laying carriage.

These cover devices can be designed in various ways. They can be formedby one or two auxiliary cover belts, which, as needed, can be pulled inand out between the upper carriage and the laying carriage. Or, with thehelp of additional deflecting rolls, one of the card transport belts canbe used as a cover belt. It is also possible to attach at least onecover plate, which projects over the buffered card web section, to theupper carriage

The paths along which the upper carriage and the laying carriage movecan be coordinated in such a way that the upper carriage always remainson one side of the laying carriage and changes only its horizontaldistance from it, depending on the length of card web which must bebuffered. Alternatively, the upper carriage can travel over the layingcarriage during the movement cycle, namely, before or no later than thetime at which the laying carriage reaches the center of its path ofmovement.

The invention is able to fulfill the buffer function with very fewadditional parts. An infeed web buffer such as that described in EP 1612 306 A1 can therefore be eliminated. In addition, the inventive webbuffer can be used to bring fluctuations in the speed of the incomingcard web, that is, fluctuations in the speed of the card transportbelts, into harmony with the previously described requirements for thelaying of the card web on the output conveyor belt. Such speedfluctuations can be the result of the running-up-to-speed of the cardingmachine or of changes over time in the stretching processes taking placein a card web stretching unit installed upstream of the fleece layingmachine. The factors which are considered in controlling the movement ofthe upper carriage versus that of the laying carriage thus include notonly the previously described reversal of direction of the layingcarriage but also the actual transport speed of the card transport beltstraveling along the laying arm.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is explained in greater detail below with reference to theembodiments illustrated in the drawings:

FIG. 1 shows a partial view of the essential elements of a firstembodiment of the invention before any braking of the upper carriage orlower carriage has occurred in the area where they must reverse theirdirection at the right edge of an output conveyor belt;

FIG. 2 shows the arrangement of FIG. 1 near the reversal point at theright edge of the output conveyor belt, where the laying carriage isbeing braked with respect to the upper carriage;

FIG. 3 shows the arrangement of FIG. 1 in the middle of the outputconveyor belt, the upper carriage and the laying carriage moving in thedirection opposite that shown in FIG. 1;

FIG. 4 shows a diagram similar to FIG. 1 near the reversal point of theupper carriage and the laying carriage at the left edge of the outputconveyor belt;

FIG. 5 shows the essential elements of a second embodiment of thepresent invention in a position near the right edge of the outputconveyor belt;

FIG. 6 shows the essential elements of a third embodiment of theinvention; and

FIG. 7 shows the essential elements of a fourth embodiment of theinvention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

According to FIGS. 1-4, the bottom end of a laying arm 3 can be movedback and forth above an output conveyor belt 1, which runs over at leastone deflecting roll 2. The laying arm 3 is jointed at an upper end (notshown) to a feed arm (not shown), which is also mounted in joints. Forfurther details, reference is made to EP 1 612 306 A1 cited in theintroduction, the content of which is included by reference in thepresent application. The bottom end of the laying arm 3 is jointed to anupper carriage 4, which can be moved back and forth transversely to thetransport direction of the output conveyor belt 1 by means of a chain, atoothed belt 5, or the like. The toothed belt 5 can be driven by a drivepinion 6, connected to a drive unit (not shown). The drive function issymbolized in FIGS. 2 and 4 by circles with two black sectors.

Two deflecting rolls 7, 8 are rotatably supported in the upper carriage4. Around them pass card transport belts 9 and 10, which are guidedparallel to each other along the section of the laying arm 3 leading tothe deflecting rolls 7 and 8 so that they can sandwich between them thecard web 11 to be laid. At a certain level below the upper carriage 4,that is, between the upper carriage 4 and the output conveyor belt 1, alaying carriage 12 is located, which, like the upper carriage 4, canmove above the output conveyor belt transversely to the transportdirection of the output conveyor belt 1. A chain or a toothed belt 13 isanchored to the laying carriage 12; as shown in FIG. 2, this chain orbelt passes around a drive pinion 14 and serves to move the layingcarriage 12 back and forth. In the laying carriage 12, two deflectingrolls 15, 16 are rotatably supported, over each of which a cover belt17, 18 passes. The cover belt 17 according to FIG. 2 passes overstationary deflecting rolls 19 a and 19 b, at least one of thesedeflecting rolls 19 a being provided with a drive unit. Comparabledeflecting rolls 20 a and 20 b are also provided for the other coverbelt 18 (see FIG. 4).

FIGS. 1 and 2 show the arrangement moving toward the right in thedrawing, which means that the laying carriage 12 is leaving the laidcard web 11 behind it on the left in the drawing.

In the example shown here, the upper carriage 4 is narrower, seen in itsdirection of movement, than the laying carriage 12. It is therefore ableto travel between the lateral frame of the laying carriage 12 in whichthe deflecting rolls 15 and 16 are supported.

A special feature of a preferred embodiment of the invention is that twoauxiliary cover belts 21 and 22 are mounted on the assembly consistingof the laying arm 3 and the upper carriage 4. The bottom end of thefirst auxiliary cover belt 21 is connected to a first transverse rod 23,which rests in a first holding device 24 provided in the right end ofthe upper carriage 4. The transverse rod 23 projects laterally beyondthe two sides of the upper carriage 4. The top end of the firstauxiliary cover belt 21 is fastened to a first tension spring 25anchored to the laying arm 3. The first auxiliary cover belt 21 runsmore-or-less parallel to the card transport belt 9, and in the lowerarea of the upper carriage 4 passes around a deflecting roll 26 on itsway to the transverse rod 23. The free, i.e., bottom end of the secondauxiliary cover belt 22 is also connected to a second transverse rod 27comparable to the first transverse rod 23 and is anchored at its otherend to the laying arm 3 by way of a tension spring 28. On the uppercarriage 4, it passes around a deflecting roll 29, which is adjacent tothe deflecting roll 8, over which the card conveyor belt 10 passes.

As can also be seen in FIGS. 1-4, catching devices 30, 31 are formed inthe laying carriage 12, one at the front, the other at rear with respectto the direction of movement, these devices being in the form ofreceiving notches in the frame parts of the laying carriage 12 at thesides with respect to the direction of movement. The catching devices30, 31 are located at a height which corresponds to that of the holdingdevices 24 for the transverse rods 23, 27.

In the following, the fleece laying method executed by this embodimentof the camel-back fleece laying machine is explained in detail byreference to FIGS. 1-4.

During operation, the laying arm 3 oscillates above the output conveyorbelt 1 transversely to the transport direction of the belt and lays thecard web 11 supplied by the card web transport belts 9 and 10 onto theoutput conveyor belt 1, where the layers of card web lie on top of eachother, overlapping each other in zigzag fashion. During normal operationof a camel-back fleece laying machine, including the normal operation ofthe inventive fleece laying machine, the speed at which the dischargegap of the laying arm 3 moves across the output conveyor belt 1 is equalto the infeed speed at which the card web transport belts 9 and 10supply the card web 11 to be laid to the laying gap. Meanwhile, thedirection in which the laying arm 3 is moving at the end of a layingmovement, that is, at the edge of the output conveyor belt 1, cannot bereversed at any desired speed, because the masses to be braked areconsiderable, and they must then be accelerated again. If the card webtransport belts 9 and 10 continue to run at constant speed while thelaying gap is braked or accelerated again at the edges of the outputconveyor belt 1 during the course of the movement of the gap across thebelt, thick areas will be formed in the laid fleece in the edge areas ofthe output conveyor belt 1. In the case of the known camel-back fleecelaying machines, this effect can be prevented only by matching the cardweb transport speed to the speed of the laying arm 3 and by providing aninfeed buffer upstream of the fleece laying machine.

In the present invention, the effect described above can be eliminated,however, by disconnecting the actual laying gap, through which the cardweb 11 is laid onto the output conveyor belt 1, from the laying arm 3.The laying carriage 12, which supports the deflecting rolls 15, 16forming the laying gap, is braked and stopped at the edge of the outputconveyor belt 1, whereas, as a result of the previously mentioneddisconnection, the transport speed of the card web transport belts 9 and10 can remain unchanged and in fact actually does remain the same.Because, however, the upper carriage 4 is allowed to travel beyond thelaying carriage 12, namely, toward the right as illustrated in FIGS. 1and 2, the card web, which continues to be supplied at unchanged speedby the card web transport belts 9, 10, is buffered in the area betweenthe laying carriage 12 and the upper carriage 4 on the upper run of thecover belt 17 or 18 located under the upper carriage 4. A bufferedsection of card web therefore builds up between the laying carriage 12and the upper carriage 4. After the laying carriage 12 has reverseddirection, the upper carriage 4 follows this reverse movement of thelaying carriage 12 and thus takes away the buffered length of card web.Before or no later than the point at which the area near the edge of theoutput conveyor belt 1 situated in the opposite direction of movement isreached and the laying carriage 12 must be braked again, a position isreached in which the upper carriage 4 is located again directly abovethe laying carriage 12. In this position, the card web 11 is dischargeddirectly from the discharge gap located between the deflecting rolls 7,8 around which the card web transport belts 9, 10 pass into the layinggap between the deflecting rolls 15, 16 in the laying carriage 12. Thisstate is illustrated in FIG. 3. Then, as shown in FIG. 4, the braking ofthe laying carriage 12 starts, and the upper carriage 4 continues totravel to the left over and beyond the laying carriage 4, completelycomparable to the method described on the basis of FIGS. 1 and 2.

The dynamics of the course of movement are as follows.

The laying carriage 12 and the upper carriage 4 travel initiallytogether to the right in the relative position shown in FIG. 1 at aspeed which is the same as that at which the card web transport belts 9and 10 are supplying the card web 11 along the laying arm 3. The coverbelt 17 under the upper carriage 4 is driven in such a way that itsupper run has the same speed as the card web 11. When the layingcarriage 12 approaches the edge area of the output conveyor belt 1, itstarts to be braked. The cover belt 17 is also braked in a correspondingmanner. The upper carriage 4, however, continues to travel uniformlyonward at unchanged speed. After the laying carriage 12 has brought to acomplete stop in its right end position, it is accelerated toward theleft. Meanwhile, the upper carriage continues to travel to the right,although at a speed which decreases twice as fast as the speed of thelaying carriage 12 increases. The speed of the upper carriage 4 is zerowhen the laying carriage 12 has reached half the speed at which the cardweb transport belts 9, 10 supply the card web 11. In this way, a sectionof card web is buffered without any tension or upsetting on the upperrun of the right cover belt 17.

Then the upper carriage 4 is accelerated in the opposite direction. Thedegree of acceleration depends on when the upper carriage 4 is intendedto catch up to the laying carriage 12 and thus also on the accelerationof the laying carriage 12. In any case, the movements of the uppercarriage and the laying carriage are coordinated with each other in sucha way that, in spite of the fact that the card web 11 continues to befed in through the gap between the deflecting rolls 7, 8 on the layingarm 3, the section of card web lying on the upper run of the cover belt17 is neither stretched nor upset. The upper carriage 4 ultimatelycatches up to the laying carriage 12 again and reaches the relativeposition shown in FIG. 3 before the braking process at the opposite edgeof the output conveyor belt 1 must be initiated. The upper carriage 4and the laying carriage 12 therefore slow down and stop, reverse theirdirection, and accelerate again with an offset in time from each other.The card web 11 remains in an unchanged state during this process; it isneither stretched nor upset, and thick areas are prevented from formingin the laid fleece.

As the laying carriage 12, starting from the position shown in FIG. 3,continues to move to the left toward the left edge of the outputconveyor belt 1, the situation shown in FIG. 4 is obtained, which is amirror image of that shown in FIG. 2, as the laying carriage 12 is beingbraked. In this position, the upper carriage 4 now precedes the layingcarriage 12 toward the left in order to take up the excess length ofcard web resulting from the braking of the laying carriage 4, thisexcess length being buffered between the laying carriage 12 and theupper carriage 4. The details of the situation in FIG. 4 do not need tobe explained separately in detail, for the situation, as previouslymentioned, is the mirror image of that shown in FIG. 2, with theexception of the angle at which the laying arm 3 slants with respect tothe upper carriage 4. The design is similar to that illustrated in FIG.1 of EP 1 612 306 A1, in that the laying arm 3 always slants away fromthe upper carriage 4 in one direction and never slants first to the leftand then to the right. This results in better guidance conditions forthe card web along the infeed arm and laying arm of the camel-backfleece laying machine.

If, as shown in FIG. 2, the upper carriage 4 is moved forward, which isto say to the right, with respect to the laying carriage 12, the secondtransverse rod 27 located at the rear with respect to the direction ofmovement is held in place by the rear catching device 31 of the layingcarriage 12, located on the left in FIG. 2, so that the second auxiliarycover belt 22 attached to the second transverse rod 27 is pulled out ofthe assembly consisting of the laying arm 3 and the upper carriage 4against the force of the tension spring 28. The movement of the uppercarriage 4 versus the laying carriage 12 to the right in FIG. 2 has theresult that the card web 11 being discharged from the discharge gapbetween the deflecting rolls 7 and 8 in the upper carriage 4 arrivesinitially on the upper run of the cover belt 17 located underneath theupper carriage 4. From there, it passes through the laying gap betweenthe deflecting rolls 15, 16 in the laying carriage 12 and arrives on theoutput conveyor belt 1. In the area between the upper carriage 4 and thelaying carriage 12, the card web 11 is covered from above by the secondauxiliary cover belt 22. After the laying carriage 12 and the uppercarriage 4 reverse their direction, and after the position shown in FIG.3 is reached, the two auxiliary cover belts 21, 22 are pulled in.Because the upper carriage 4 is leading the laying carriage 12 towardthe left, it pulls the first auxiliary cover belt 21 out of the assemblyconsisting of the laying arm 3 and the upper carriage 4, as FIG. 4shows, in a manner similar to the situation explained on the basis ofFIG. 2, as a result of which the section of the card web 11 lying on theother cover belt 18 is covered.

FIG. 5 shows a modification of the embodiment of the invention accordingto FIGS. 1-4. The embodiment according to FIG. 5 differs from that ofFIGS. 1-4 in that, here, the upper carriage 4 does not travel across thelaying carriage 12, i.e., moving from a position in which the uppercarriage 4 is to the right of the laying carriage 12 to a position inwhich the upper carriage 4 is to the left of the laying carriage 12.Instead, the upper carriage 4 in the example shown here is always to theright of the laying carriage 12. The upper carriage 4 and the layingcarriage 12 are connected to the previously described drive units.Because the same reference numbers are used, there is no need to repeatthe explanation. Because of the special nature of the design, only oneauxiliary cover belt 22 is attached to the assembly consisting of thelaying arm 3 and the upper carriage 4; this auxiliary belt is connectedat all times to the laying carriage 12. The operation of this fleecelaying machine is described in the following.

During normal operation, the laying carriage 12 and the upper carriage 4are moved at uniform speed transversely across the output conveyor belt1. The upper carriage 4 is located just to the right of the layingcarriage 12, that is, in front of the laying carriage 12, under theassumption that the direction of movement is toward the right, or behindthe laying carriage 12, if the direction of movement is toward the left.

When the laying carriage 12 reaches the area of the right edge of theoutput conveyor belt 1, it is braked, while the upper carriage 4continues to travel at the same speed, thus bringing about the effectthat the excess length of card web, which results from the unchangedsupply speed of the card web transport belts 9, 10, is buffered betweenthe upper carriage 4 and the laying carriage 12 on the upper run of thecover belt 17. To this extent, this method is similar to that which wasexplained on the basis of FIG. 2. The sequence of movements after thereversal of direction and the re-acceleration of the laying carriage isalso the same as that explained on the basis of FIG. 2. That is, afterthe laying carriage has reached its final speed, the distance betweenthe upper carriage 4 and the laying carriage 12 is the same again as theoriginal distance.

When the laying carriage 12, during its movement to the left, duringwhich the freshly laid card web lies under the lower run of the coverbelt 17, is braked, a buffer must be built up again. This is done in thepresent case by braking the upper carriage 4 twice as fast as the layingcarriage 12, so that it comes to a stop before the laying carriage 12has reached its reversal point. During the rest of the braking period ofthe laying carriage 12, the upper carriage 4 is accelerated in thedirection opposite that in which the laying carriage 12 is moving untilit reaches the original speed, which corresponds to the transport speedof the card web transport belts 9, 10. Then the laying carriage 12 isaccelerated again, so that it starts to follow the upper carriage 4 andfinally catches up to it. The laying carriage 12 has enough time to dothis, because the period of time over which it can be accelerated can beextended all the way to the point at which a buffer volume must be builtup in the area near the right edge of the output conveyor belt 1.

The exemplary embodiment according to FIG. 6 is similar that of FIG. 5to the extent that here, too, the upper carriage 4 is always on one sideof the laying carriage 12. In the example shown here, it is always onthe right side of the laying carriage 12. The sequence of movements inthis embodiment of the invention is also completely the same as that ofthe embodiment according to FIG. 5, for which reason it is possible toomit an explanation. The difference pertains to the way in which thelength of card web being buffered during operation is protected from airturbulence.

In the embodiment according to FIG. 6, the upper carriage 4 projects onthe side where the buffer is built up on the cover belt 17 during thebraking of the laying carriage 12. This projection takes the form of anextension 32, at the free end of which a third deflecting roll 33 issupported at a level corresponding to that of the deflecting roll 8. Inaddition, a fourth deflecting roll 34 is supported in the upper carriage4 near the hinge point of the laying arm 3 of the carriage. The card webtransport belt 10 passing over the deflecting roll 8 also passes aroundthe third and fourth deflecting rolls 33, 34, before it returns alongthe laying arm 3 to the infeed arm (not shown). In the section betweenthe deflecting roll 8 and the third deflecting roll 33, this card webtransport belt extends parallel to and a short distance above the coverbelts 17, 18. When, during the braking of the laying carriage 12, abuffer volume builds up on the upper run of the cover belt 17, asdescribed on the basis of the embodiment of FIG. 5, the section of cardweb located on the cover belt 17 is covered by the card web transportbelt 10, which in this area thus acts as an auxiliary cover belt, whichmoves at the same speed and in the same direction as the section of cardweb covered by it.

When an embodiment of the invention corresponding to FIG. 6 is to bedesigned in such a way that that the upper carriage is to travel acrossthe laying carriage in the manner explained on the basis of FIGS. 1-4,the upper carriage should be designed symmetrically. That is, extensionswill be provided on both sides, at the front and at the rear, of theupper carriage, and the card web transport belt 9 will also be used asan auxiliary cover belt.

The embodiment according to FIG. 7 is related to that shown in FIG. 6 tothe extent that the means for covering the buffered length of card webare formed as devices projecting from the upper carriage 4. Under theassumption that that the upper carriage 4 is to travel over the layingcarriage 12 in the manner of the embodiment of FIGS. 1-4, these devicesare realized as projecting plates 35 as shown in FIG. 7, one at thefront, the other at the rear of the upper carriage 4. The plates 35 arearranged a short distance above the upper run of the cover belts 17, 18and are able to shield the length of card web present there from airturbulence. For the rest, the features shown in FIG. 7 correspond tothose of the preceding exemplary embodiments, as indicated by the use ofthe same reference numbers, for which reason there is no need to repeatthe explanation.

If this fleece laying machine is intended to operate in the mannerexplained above on the basis of FIG. 5, a plate 35 must be provided onlyon the side of the upper carriage 4 which is facing the laying carriage12, because a volume of buffered card web which must be protectedagainst air turbulence is built up only on this side.

In the preceding description, the position of the reversal-of-directionpoints has always been described with reference to the edges of theoutput conveyor belt. It is obvious that the invention also applies inthe same way to cases in which a relatively narrow fleece is to be laidon a relatively wide output conveyor belt, which means that the fullwidth of the output conveyor belt is not being utilized. It is thereforealso possible to define the locations of the reversal-of-directionpoints as the ends of the path along which the laying carriage lays thecard.

1. A camel-back fleece laying machine with a laying arm, a top end ofwhich is attached to a joint, two endless card web transport belts beingguided along the arm, a bottom end of the arm, which is connected by ajoint to an upper carriage, being provided with an output gap; and thearm being guided by the carriage along a path which is transverse to thetransport direction of an output conveyor belt in a plane above thisbelt, where the upper carriage is connected to a first drive unit, whichcauses the laying arm to oscillate; and with a laying carriage, which isguided at a certain height between the output conveyor belt and theupper carriage on a path extending parallel to the upper carriage, andin which two deflecting rolls are supported close together, over each ofwhich a cover belt passes, where the two cover belts form a laying gapat the deflecting rolls, through which the card web being supplied bythe card web transport belts is guided, and have upper and lower runs,which extend in upper and lower planes parallel to the output conveyorbelt, the lower plane being very close to the output conveyor belt, andwhere the laying carriage is connected to a second drive unit, whichcauses the carriage to move back and forth across the output conveyorbelt, this drive unit being independent of the first drive unit, i.e.,of the drive unit of the upper carriage, and where at least at one end,the path of the upper carriage extends beyond the path of the layingcarriage to form a web buffer.
 2. The fleece laying machine according toclaim 1, further comprising devices for covering a section of card webwhich has been discharged from the discharge gap of the laying arm ontothe upper run of one of the cover belts.
 3. The fleece laying machineaccording to claim 1, wherein the paths of the laying carriage and theupper carriage are coordinated with each other in such a way that theupper carriage cannot travel over the laying carriage.
 4. The fleecelaying machine according to claim 3, wherein an auxiliary cover belt ismounted on the laying arm on the side facing the laying carriage in aposition between the upper carriage and the laying carriage, thisauxiliary belt being connected to the laying carriage and set up in sucha way that that it can be pulled out of a retracted position into anoperating position, in which it partially covers the upper run of thecover belt located under the discharge gap of the laying arm, andretracted from that position again.
 5. The fleece laying machineaccording to claim 3, wherein a first auxiliary deflecting roll issupported in the upper carriage on the side facing the laying carriage,a certain horizontal distance away from the discharge gap of the layingarm, and at the same height as that arm, and in that a second auxiliarydeflecting roll is supported near the laying arm, where the card webtransport belt, which leaves the discharge gap of the laying arm on theside facing the laying carriage, passes around these deflecting rolls.6. The fleece laying machine according to claim 3, wherein a freelyprojecting cover plate, which extends over the upper run of the coverbelt located underneath the upper carriage, is attached to the uppercarriage on the side facing the laying carriage.
 7. The fleece layingmachine according to claim 2, wherein the paths of the laying carriageand the upper carriage are coordinated with each other in such a waythat the upper carriage cannot travel over the laying carriage.
 8. Thefleece laying machine according to claim 7, wherein an auxiliary coverbelt, which can be connected to the laying carriage, is mounted on thelaying arm on a side facing the laying carriage, this auxiliary coverbelt being set up so that, as a function of the positional relationshipbetween the upper carriage and the laying carriage, it can be pulled outof a retracted position into a working position, in which it partiallycovers the upper run of the cover belt located under the discharge gapof the laying arm, and moved back into the retracted position again. 9.The fleece laying machine according to claim 7, wherein a firstauxiliary deflecting roll is supported in the upper carriage on a sidefacing the laying carriage a certain horizontal distance away from thedischarge gap of the laying arm and at the same height as that arm, andin that a second auxiliary deflecting roll is supported near the layingarm, where the card transport belt, which leaves the discharge gap ofthe laying arm on a side facing the laying carriage, passes around thesetwo deflecting rolls.
 10. The fleece laying machine according to claim7, wherein a freely projecting cover plate is attached to the uppercarriage (4) on a side facing the laying carriage, the cover plateextending over the upper run of the cover belt located under the uppercarriage.
 11. The fleece laying machine according to claim 1, whereinthe path of the upper carriage extends beyond the path of the layingcarriage at both ends of the path of the laying carriage.
 12. The fleecelaying machine according to claim 11, wherein an auxiliary cover belt ismounted on the laying arm, one on each side of the discharge gap, thesebelts being set up so that they can be pulled out of a retractedposition into a working position partially covering the upper run of oneof the cover belts; a holding device for keeping ready a free end of theauxiliary cover belt on the side in question is formed in the uppercarriage on each side of the discharge gap; and catching devices areformed in the laying carriage, these devices being designed so that,when the upper carriage travels beyond the path of the laying carriage,they can grip the free end of the auxiliary cover belt located in therear with respect to the direction of movement of the discharge gap andthus pull the auxiliary cover belt over the other run of the cover beltlocated under the upper carriage.
 13. The fleece laying machineaccording to claim 11, wherein a first auxiliary deflecting roll issupported in the upper carriage a certain horizontal distance away fromthe discharge gap of the laying arm and at the same level as the gap,and in that a second auxiliary deflecting roll is supported near thelaying arm, where the card web transport belts, which leave thedischarge gap of the laying arm, pass around these auxiliary rolls. 14.The fleece laying machine according to claim 11, wherein a freelyprojecting cover plate, which extends above the upper run of the coverbelts, is attached to the upper carriage on both sides.
 15. A method forlaying a fleece by means of a camel-back fleece laying machine, in whicha card web supplied by a carding machine is guided between two card webtransport belts guided in parallel at uniform speed along a movablelaying arm, the card web thus arriving at a discharge gap, which isguided along a first path of movement and is disposed at the bottom endof the laying arm, from which said card web travels onward to a layinggap, the laying gap being located between two cover belts, which aredeflected around two deflecting rolls mounted in a laying carriage,which is moved back and forth along a second path of movement, the cardweb thus being laid on an endlessly moving output conveyor beltextending transversely to the laying web, where, when the layingcarriage is braked as it approaches one of its reversal points, thespeed of the card web transport belts remain unchanged and the dischargegap is moved with respect to the laying gap in such a way that thedistance between the discharge gap and the laying gap is increased, sothat a certain length of the card web can be buffered between thedischarge gap and the laying gap, whereupon, after the laying carriagehas reversed direction and is accelerating again, the distance betweenthe discharge gap and the laying gap is decreased in such a way that thelength of buffered card web is reduced.
 16. The method according toclaim 15, wherein the discharge gap is maintained above the laying gapwhile the laying carriage is moving at uniform speed.
 17. The methodaccording to claim 15, wherein the discharge gap and the laying gap aremaintained at a lateral offset from each other over their entire pathsof movement.